The present invention relates generally to multimedia systems, and more particularly, to systems, methods and computer products for content-derived (generated) metadata.
The term “metadata” refers to data which describes characteristics of other data. For example, metadata associated with a computer word processing file might include the title of the document, the name of the author, the company to whom the document belongs, the dates that the document was created and last modified, keywords which describe the document, and other descriptive data. While some of this information may also be included in the document itself (e.g., title, author, and data), metadata is a separate collection of data which may be stored separately from, but associated with, the actual document. One common format for documenting metadata is eXtensible Markup Language (XML). XML provides a formal syntax which supports the creation of arbitrary descriptions, sometimes called “tags.” An example of a metadata entry might be <title>War and Peace</title>, where the bracketed words delineate the beginning and end of the group of characters that constitute the title of the document which is described by the metadata.
In the example of the word processing file, the metadata (sometimes referred to as “document properties”) is generally entered manually by the author, editor, or document manager. However, manual entry of metadata can be laborious, and is frequently skipped. However, metadata provides a critical capability used by search engines.
Internet photo management services exemplify one approach to the creation of metadata. Photo sharing sites usually propose several ways to classify images. For example, most sites propose at least a taxonomy where images can be grouped within a directory-like structure in so-called “galleries”. Some sites also allow users to classify images using tags to build a folksonomy. Depending on the restrictions on the set of users allowed to tag a single document and the set of tags available to describe the document, one speaks about narrow and broad folksonomies. A folksonomy is broad when there is no restriction on the set of taggers and available tags. When there are limitations, the folksonomy is called narrow. Another mechanism is coupling taxonomy and folksonomy, where tags associated to galleries and artists are cascaded to the galleries and artist's pictures.
While this method produces interesting and generally useful results, it requires that the media to be described be published and widely distributed, usually on the Internet. In addition, the “folksonomy” approach to metadata creation can produce seemingly random, frivolous, amusing, or “niche interest” tags. (Note that the term “tag” used here is slightly different from the XML term previously described, but the terms are clearly related.)
Because of the benefits of metadata in searching, especially for non-text data such as sound or image, and because of the difficulty of manually entering metadata, and because of the limitations of folksonomy-based metadata, there is a need for an automated method to create metadata based on the content of the media file(s) of interest.